Activity: Talk or presentation types › Oral presentation
Description of Activity
Gave a presentation entitle 'Obtaining smooth distances from a lumpy universe.'
How do we appropriately fit a model based on an idealised Friedmann-Lemaître Robertson-Walker (FLRW) spacetime to observations made from one location in a lumpy Universe? We address this question for the apparent magnitude of Type 1A supernova (SN1A) and the acoustic peaks in the density field by calculating the cosmological distance in a perturbed universe. We find that at low redshift, the FLRW spacetime predictions for the cosmological distance receive corrections from the perturbations of the redshift due to peculiar velocities. We show how this correction could impact the determination of the Hubble rate from the BAO measurements and the calibration of SN1A absolute magnitude that depends on the local distance anchors.